Cultured milk products have been enjoyed in the Middle East, Europe, and parts of Asia for centuries. The Greeks felt that yogurt had therapeutic qualities for diseases caused by intestinal disorders. Bulgarians attribute their good health and longevity in part to their daily intake of cultured milk products.
The most common of the cultured milk products are yogurt, kefir, piima, buttermilk, and quark or cottage cheese.
Yogurt is simply milk thickened to a custard consistency by certain acid-forming bacteria growing in it. The special bacteria that turn milk into yogurt are lactobacillus bulgaricus, lactobacillus acidophilus, and streptococcus thermophilus. The coagulation and the fermentation of milk sugar into lactic acid is caused by these bacteria. This action curdles the protein in yogurt and acts as a preservative.The bacteria in yogurt have already begun to break down the protein molecules into lactic acid, making it easy for the body to assimilate. Thus yogurt is helpful for people who have lactose intolerance, because they lack an enzyme that helps to digest milk sugar in regular milk. Yogurt helps the digestion process to move along smoothly and quickly.Some doctors prescribe yogurt to replace normal intestinal flora that are destroyed when oral antibiotics have been used for an extended period of time. Antibiotics destroy “good” bacteria along with the “bad” bacteria.Buttermilk is really the liquid left from butter making.The “buttermilk” found in stores is a cultured milk made from pasteurized skim milk. Lactic acid bacteria is added to the milk and the mixture is left to clabber at room temperature.Homemade buttermilk can be made by adding a culture to pasteurized milk or, if you make your own butter, from pasteurized real buttermilk.